Method of forming a continuous tobacco filler



May 7, 1963 R. LANORE 3,088,467

METHOD OF FORMING'A CONTINUOUS TOBACCO FILLER R. LANoRE 3,088,467

METHOD OF FORMING A CONTINUOUS TOBACCO FILLER May 7, 1963 5 Sheets-Sheet 2 Original Filed DeC. 11, 1957 May 7, 1963 R. LANORE 3,088,467

METHOD OF FORMTNC A CONTINUOUS TOBACCO FILLER Original Filed Dec. 11, 1957 5 Sheets-Sheet 5 8 Rnqmann Lamme 5) (UaIAm C021,

GM 4 LUM ATTO/QA/EYS R. LANORE 3,088,467

METHOD OF FORMTNG A CONTINUOUS TOBACCO FTLLER May 7, 1963 Original Filed Deo.

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METHOD OF FORMING A CONTINUOUS TOBACCO lFIIILLER Original Filed Dec. 1l, 195? 5 Sheets-Sheet 5 United States Patent @hice 3,086,467 Patented May 7, 1963 3,088,467 METHOD F FORMING A CONTINUGUS TGBACC() FILLER Raymond Lahore, Paris, France, assignor to Usines Decoufle SA., Paris, France, a French company Original application Dec. 1l, 1957, Ser. No. 702,104, now Patent No. 3,030,966, dated Apr. 24, 1962.. Divided and this application Sept. 19, 1961, Ser. No. 139,827

1 Claim. (Cl. 131-20) This application is a division from my co-pending application Serial No. 702,104, tiled December 1l, 1957, now Patent No. 3,030,966, and concerns an improved method of forming a continuous tobacco ller, for example in a cigarette-making machine.

One diiculty that arises in the formation of a continuous tobacco iller by known methods is the tendency for the ller to contain varying quantities of tobacco along its length. In continuous rod cigarette-making machines it is usual to shower cut tobacco on to a travelling conveyor so as .to form a loose tobacco stream which is subsequently compressed laterally and enclosed in a continuous web of cigarette paper to form a continuous cigarette rod. The loose stream formed on the conveyor is usually irregular in that the quantity of tobacco varies from point to point along its length, and these irregularities are generally also found, to a greater or less extent, in the filler of the wrapped cigarette rod, in spite of various means which have been used to improve the uniformity of the tobacco ller before it is enclosed in the paper wrapper. The present invention is directed to the problem of forming a tobacco ller of improved uniformity.

For this purpose the present invention provides a method of producing a continuous tobacco tiller by trimming a tobacco stream to a desired cross-sectional size, the stream being conveyed from a position at which it has been built up, to a trimming position, While subjecting it to air pressure directed against the tobacco in a direction transverse to the direction of movement of the stream. The air-pressure may be applied by applying suction to a conveyor carrying the stream, which effects substantial lateral compression of the stream, for example, to a density at least half that required in the final product of the machine (e.g. a cigarette).

As used herein, the terms tobacco ller and tobacco rod are intended to designate the narrow stream (conventionally formed by showering tobacco particles on a conveyor), which stream is fed toward cigarette rod forming mechanism in which cigarette paper is wrapped around the tobacco rod to form the continuous 'nislied cigarette rod.

Apparatus in accordance with the invention, for forming a continuous tobacco ller in a cigarette-making machine, will now be described by way of example with reference to the accompanying drawings, in which:

FIGURE l is a sectional end eleva-tion diagrammatically illustrating apparatus according to the invention;

FIGURE 2 is a sectional front elevation;

FIGURE 3 is a plan view of part of the apparatus shown in FIGURES 1 and 2;

FIGURE 4 is a sectional view taken along the line IV-IV, FIGURE 2;

FIGURE 5 is a sectional View taken along the line V-V, FIGURE 2; and

FIGURE 6 is a sectional view taken along the line VI-VI, FIGURE 5.

Referring rst to FIGURE 1, the apparatus comprises a hopper 1 for cut tobacco, a conveyor belt 2 to support tobacco in the hopper, and a carded roller 3 towards which tobacco is urged by the conveyor belt 2, which move in the direction shown by the arrow. A brushing or levelling roller 4 is located adjacent the roller 3' and rotates in the same direction, as indicated by the arrows on the rollers 3 and 4. A picker roller 5 is arranged close to the roller 3 and is rotatable so as to pick tobacco from the carding of the roller 3 and distribute it on an endless conveyor belt 6. The conveyor 6 is arranged to move in the direction of the arrow at a speed of 4 feet per second.

Beyond the end of the upper run of the conveyor 6 is a passage 8 which extends along the whole width of the conveyor belt 6, see FIGURE 2. The passage 8 comprises opposed walls, spaced 10 mm. apart, whose opposed surfaces are slippery to reduce friction. These walls extend upwardly and their upper extremities are connected to a pair of side guides or walls which form a channel 9, as best seen in FIGURE 4. The walls of the channel 9 have slippery opposed surfaces, the upper parts of which are convergent (considered in a downward direction), each being at an angle of 10 to rthe vertical. A flat endless conveyor belt 10, which is l0 mm. wide, is arranged to move through the upper part of the channel 9, and passes wheels or rollers x11, 12 and 13 (see FIGURE 2) of which the roller =11 drives the belt. The conveyor belt l0 is perforated, being provided with small holes each of a diameter of 0.8 yto 1.2 mm. About 40 such holes per square centimetre of the entire surface of the belt are provided.

The belt 10 is held within the channel 9 by the lower surfaces of a pair of opposed elements 14, which overhang the Walls of the channel 9 by about 1 mm. on each side, thus forming shoulders which guide the belt through the channel.

The channel 9 and conveyor belt 10 are slightly inclined downwardly in the direction of movement of the band. This inclination may for exarnple be at an angle of 6 to 10 tothe horizontal.

A suction chamber l5 communicates with the perforated conveyor belt 10 by way of a narrow chamber 16 formed by the opposed elements 14. The chamber 15 further communicates with a pipe 17, `FIGURES l and 2, which extends to the inlet of a fan (not shown) arranged to draw air through the pipe l17 from the chambers 15 and 16 and thus through the perforated conveyor belt 10.

The passage S extends downwardly below the conveyor belt 6, and communicates with a pipe Z1 which extends to the output side of the fan referred to above, so that air is blown through the pipe 21 into and through the passage 8. As illustrated in FIGURE 2, the air sucked through the conveyor 10 between the points marked -18 and 19 in the figure reaches the conveyor from the passage 3, While between the points marked 19 and 20 the air is drawn through the channel 9, whose opposed sides are extended downwardly by guide plates 22.

The arrangement of the fan, the pipe 17, and the suction chambers 15 and 16, is such that a negative pressure of about 800 to 900 mm. of water is maintained in the chamber 16.

A trimming device for trimming the tobacco liller is provided beneath the channel 9 at a position beyond the passage A8, that is, between the points marked 19 and 20 in FIGURE 2. The trimming device comprises a pair of peripherally chamfered discs 23 mounted on two rotating spindles 24 driven by pinions 25. The discs are arranged to be rotated in opposite directions as indicated in FIGURE 3, with a peripheral speed slightly greater than the linear speed of the conveyor -belt 10. The two discs 23 have their bottom surfaces disposed in a single plane parallel to the plane of the flat conveyor belt 10. Although in the drawings the discs are shown apparently in contact, their opposed edges are,lat the 3 point where they are closest to each other, separated by a distance of 0.1 to 0.2 mm.

Beneath the trimming device is a paddle-wheel device 26 for removing tobacco which is separated from the filter by the discs 23. This comprises a hub 27 provided with four radial `blades 28, each about 8 rnrn. wide. The hub is mounted on the end of a spindle 29 which is arranged to rotate at high speed and is inclined to the direction of movement of the conveyor belt 1G. The blades 28 are adjusted so that their extreme edges rub against the bottom Isurface of both the discs 23 at the region 4where the edges of the two discs approach closest to each other, and thus engage and remove tobacco which is -beneath the discs, completing the separation of that tobacco from the tobacco that passes above the discs.

An endless conveyor 30 extends beneath the rotating paddle-wheel 26 to receive tobacco removed and thrown downwardly by the blades 28. The conveyor 30 is arranged to convey such tobacco towards, and deposit it upon, a further conveyor 31 (FIGURE l) which in turn deposits the tobacco on the conveyor band 2, which returns it to the hopper 1.

Means are provided for adjusting the position of the trimming device, in order to alter the level at which tobacco is separated `from the filler carried ,by the conveyor 10. A frame 32 (FIGURES 5 and 6) supports bearings 33 for the spindles 24 of the discs 23, and also the bearing 34 for the shaft 29 of the paddle-wheel 26. The frame 32 has a slide 36 which is slidable in a guideway 136 in a stationary frame 38. A tapped member 37 is carried by the slide 36, and a screw 39 which extends through the frame 38 is threaded through the member 37 and can be rotated by a knob 40 in order to raise or lower the frame 32, and therefore the discs23 and the paddle-wheel 26. The latter can move up and down with the frame 32 because its spindle 29 includes a universal joint 35.

In the construction illustrated, the minimum distance of the edges of the discs 23 from the conveyor belt 10 is 9 mm., and this distance can if required be increased, by lowering the frame 32, by any suitable amount.

In practice it is found that this distance can be increased from 9 mm. to 12 mm. with satisfactory results. The minimum distance of 9 mm. is of course determined by the walls of the channel 9. If it is desired to position the discs 23 still closer to the conveyor 10, this can be done by making the channel less deep, or in other words by making the channel walls narrower.

Referring now to FIGURE 2, an endless conveyor belt 41 is arranged to carry a continuous web 42 of cigarettepaper through rod-forming mechanism, including a tongue 43, `by which the tobacco ller is enclosed in the cigarettepaper web to form a continuous cigarette rod. The belt 41 and cigarette-paper web 42 extend `beneath part of the conveyor `10, and move at the same speed as the conveyor and in the same general direction, although in the construction shown, the belt 41 runs horizontally while the conveyor 10 is slightly inclined downwardly in its direction of movement.

The suction chamber 16 extends to the point marked 20, FIGURE 2, and beyond that point the conveyor 10 is no longer in communication with the source of suction. The paper web 42 is led in beneath the conveyor 10 just before the latter reaches the point 20, and is thus in a position to receive and support the tobacco filler when this is no longer held by suction against the conveyor 10. The spacing between the paper web 42 and the conveyor 10 is at no point greatly in excess of the depth of the tobacco ller, and is preferably approximately equal to the depth of the filler, so that the latter can be transferred from the conveyor to the paper without any substantial drop and thus with little disturbance.

A shoe 44 is arranged between the tongue 43 and the roller 11 and has an edge just clear of the conveyor 10 to prevent tobacco being carried around the roller 11 by the conveyor 10.

The belt 41 is supported in a trough 141 which shapes it and the paper web 42 into arcuate form in the usual way.

The operation of the apparatus is as follows.

Tobacco is fed from the hopper 1 by the carded roller 3, on which it forms a carpet or layer from which surplus tobacco is brushed back `by the brushing roller 4. The picker roller 5, rotating at high speed, picks tobacco from the carding of the roller 3 and throws it on to the conveyor 6, which as stated above is moving at a speed of 4 feet per second. This speed is high relative to the peripheral speed of the carded roller 3, and the tobacco is thus spread or distributed over the conveyor 6 fairly sparsely and in a somewhat separated condition.

Adjacent the point 7, FIGURE 1, the conveyor 6 passes over a guide roller and, due to the speed of the band 6, the tobacco is projected towards the passage `8. The distance from the point 7 (that is, the end of the conveying surface of the conveyor 6) to the passage 8 is, in the example illustrated, about 6 inches.

The passage 8 is so arranged and dimensioned in relation to the suction fan and the various air conduits that a stream of air flows upwardly through the passage 8 at a velocity of 30 feet per second. As stated above, the opposed walls of the passage 8 are spaced l0 mm. apart. This arrangement, whereby air flows at a speed of 30 feet per second through a 10 mm. passage, is found to give good results. Both the air speed and the dimensions of the passage may be varied if desired, but in any such case it is found preferable that the relationship between the air speed in the passage, and the spacing between the passage walls, should be governed by the formula V=300/T, where V=velocity of air in feet per second, and T=the distance between the walls of the passage (or -in other words the depth of the stream of air) in millimetres.

As mentioned above, the tobacco is distributed over the conveyor 6 in a somewhat separated condition-that is to say, the individual shreds or particles of tobacco are to a considerable extent separated from one another by the picking operation and are distributed over the surface of the conveyor 6 in a similar condition owing to the high speed of the conveyor 6 relative to that of the carded roller 3.

These particles of tobacco, moving at a speed of 4 feet per second, are projected into the passage 8 and thus immediately subjected to the action of a stream of air moving .upwardly through the passage at a speed of 30 feet per second. Thus successive particles of tobacco are suddenly and violently accelerated by the rapid upward current of air. This sudden acceleration greatly increases the separation of particles from one another, and tends to space individual particles apart from one another to a considerable extent, resulting in a rapid upward flow of separated particles most of which are spaced well apart from each other.

These particles are thus carried at high speed up into the channel 9 where they accumulate on the underside of the conveyor 10, and on each other, to form a filler. The particles are held to the conveyor 10 by suction acting through the small -holes in the conveyor.

By the device disclosed a tobacco filler is built up of substantially uniform density. The expression substantially uniform density must not, however, rbe understood as meaning necessarily a density which is uniform throughout the depth of the filler. The forces acting on the particles of tobacco at different depths or levels of the ller, as the latter is built up in the channel 9, may be Vaffected by the changing quantity of tobacco held against the perforated conveyor, in such a way as to produce a greater density of tobacco at one level than at another.

The `density at any one level is, however, thought to be substantially the same along the length of the ller (excluding any parts of the filler whose density may be deliberately increased by some means other than' the impact of tobacco under the iniiuence of the air stream).

The walls of the channel 9v -being convergent (considered in a ydirection away from the conveyor tend to give some support to the ller in .addition to that lgiven by suction.

As stated above, the walls of the channel 9 are slippery, and consequently they oiier low resistance to the tobacco liller formed in the channel 9. The eiect, therefore, is that the filler is conveyed forward by the conveyor and subjected to the minimum of disturbance along its length.

Tobacco is fed to the passage 8 in suiiicient quantity, in relation to the speed of the conveyor 10, to enable a ller kto be built up on the conveyor of greater depth than is required in the iinal iiller. The filler so formed may varry in ydepth from point to point along its length, but its minimum depth should, as far as is practicable, be at least equal to the distance between the conveyor 10 and the discs 23 of the trimming device which removes excess tobacco and thereby trims the lller to a uniform depth. Since the width of the filler is controlled by the side walls of the channel 9, it will be seen that the filler after trimming, being of substantially uniform density along its length (in the sense explained above) and now having a substantially uniform cross-sectional size, is capable of being compressed to cigarette-rod size while maintaining to a very great extent the uniformity of its density.

In the construction described, where a negative pressure of 800 to 900 of water is maintained in the cham-ber 16, and where air is blown at a velocity of 30 feet per second upwardly through lthe passage 8 whose walls are 10 mm. apart, it is found that a filler of a part'ioular type and moisture content can be formed on the conveyor 10 with a density equal to at least half the density required in the final ller-that is, when it has been compressed beneath the tongue 43 and enclosed in the paper web 42.

The amount of pressure exerted on the tobacco to compact it to at least half -the final density will of course vary with the kind and condition of the tobacco being used.

Accordingly such pressure will vary according to immediate needs.

The trimmed lfiller is carried past the point 20, FIG- URE 2, beyond which it is no longer held to the conveyor 10 by suction. By this time, however, it has been led over the paper web 42 which is moving at the same speed as the filler `and is close enough to the conveyor 10 to receive the filler from the conveyor without the iller being subjected to any substantial drop or other disturbance. lThus the structure of the iiller which has been formed land trimmed on the conveyor lil is little disturbed during transfer to the paper web.

The iinal compression of the iiller under the tongue 43, and its enclosure in the paper web 42 .to form a continnous Wrapped cigarette rod which is severed to produce individual cigarettes, follows conventional practice and need not be described.

What I claim as my invention and desire to secure by Letters Patent is:

In the manufacture of cigarettes on a continuous rod cigarette making machine, a method of producing a continuous trimmed tobacco rod, comprising the steps of building up a continuous tobacco rod containing a surplus of tobacco over that in the trimmed rod, conveying the built up rod 'by means of a conveyor to a position at which the rod is trimmed by removal of said surplus tob-acco while conning the sides of the tobacco rod, at least adjacent the conveyor, and subjecting the tobacco rod, during a part at least of its passage to the said position', to air pressure 4directed against and through the tobacco rod and the conveyor in a direction transverse to the direction of movement of the tobacco rod to cause compression in said rod, at least part of said compression existing at said trimming position.

References Cited in the tile of this patent UNITED STATES PATENTS 1,808,795 Stelzer June 9, 1931 2,660,178 Rault Nov. 24, 1953 FOREIGN PATENTS 218,648 Australia Nov. 12, 1958 1,179,992 'France Dec. 29, 1958 854,736 Great Britain Nov. 23, `1960 

